Earth’s orbital debris – it’s a drag

LEO640[1]

Debris in low Earth orbit – the region of space within 2,000 km of the Earth’s surface. It is the most concentrated area for orbital debris. Approximately 95% of the objects in this illustration are orbital debris, i.e., not functional satellites. The dots represent the current location of each item. The orbital debris dots are scaled according to the image size of the graphic to optimize their visibility and are not scaled to Earth. Graphic from NASA’s Orbital Debris Program Office http://orbitaldebris.jsc.nasa.gov/index.html

From the Global Aerospace Corporation

Removing orbital debris with less risk

Global Aerospace Corporation (GAC) announced today that the American Institute of Aeronautics and Astronautics (AIAA) is publishing an article entitled “Removing Orbital Debris With Less Risk” in the March/April edition of the Journal of Spacecraft and Rockets (JSR) authored by Kerry Nock and Dr. Kim Aaron, of GAC, and Dr. Darren McKnight, of Integrity Applications Incorporated, Chantilly, VA. This article compares in-orbit debris removal options regarding their potential risk of creating new orbital debris or disabling working satellites during deorbit operation.

Space debris is a growing problem in many orbits despite international debris mitigation guidelines and policies. While this space environmental issue has been discussed and studied for years, many critical parameters continue to increase. For example, the number of significant satellite breakup events has averaged about four per year. Removing large amounts of material already in orbit has been a major issue for debris mitigation strategies because a large object, like a satellite or spent rocket stage, is not only more likely to be involved in an accidental collision due to its large collision cross-section but the large mass has the potential to be the source for thousands and thousands of smaller, but still dangerous, debris if involved in a collision.

Deorbit devices have been proposed for dealing with the growing problems posed by orbital debris. The authors describe these devices that can use large structures that interact with the Earth’s atmosphere, magnetic field or its solar environment to deorbit large objects more rapidly than natural decay. Some devices may be better than others relative to the likelihood of collisions during their operation. Current mitigation guidelines attempt to address this risk by calculating an object’s atmospheric drag area times its orbit decay time to compare the probability of a large object experiencing a debris-generating impact. However, the authors point out that this approach is valid only for collisions with very small debris objects. Since the peak in the distribution of the area of orbital debris occurs for objects with a size close to 2 m, some of which are operating satellites, it is important to incorporate an augmented collision cross-section area that takes into account the size of both colliding objects. This new approach leads to a more valid comparison among alternative deorbit approaches.

This graph displays the area-time product summary comparison of the several deorbit devices evaluated for their risk. High-energy collisions can create significant amounts of new and dangerous orbit debris and low-energy collisions, while not generating significant new debris, can disable operating satellites. Area-time product, measured in square meters per year, is the product of collision cross-section area multiplied by the time for the object to reentry the atmosphere. Credit: Global Aerospace Corporation

Two other factors that affect the potential risk of a particular deorbit device are the nature of hypervelocity impacts and the level of solar activity. The authors describe the physics of hypervelocity impacts in space that can affect the assessment of risk. In addition, they describe how solar activity level affects the decay process and alters the result of the calculation of collision cross-section area times decay time, which is a measure of the risk of the deorbit device. The authors also characterize two types of collision risk, that is, the risk of creating new debris-generating objects in hypervelocity impacts by high-energy collisions and the risk of disabling operational satellites by low-energy collisions.

The implication of this new approach to determining risk indicates that ultra-thin, inflation-maintained drag enhancement devices pose the least risk of creating new debris or disabling operating satellites, while electromagnetic tethers are shown to have a very large risk for disabling operating satellites. All deorbit devices studied appear to have less risk than leaving an object in orbit even for only 25 years, which may suggest a possible need to reconsider current orbital debris mitigation guidelines that allow objects to remain in orbit that long.

“As the orbital debris hazard increases, it will be critical that the community can use techniques that have high operational effectiveness and low risk. Inflatables have been the best balance for that approach in my mind and I hope that this paper exposes more of the aerospace industry to the benefits of using inflatables to accelerate the reentry of non-operational spacecraft,” said Dr. McKnight.

Finally, atmospheric drag deorbit devices are found to be much more efficient during periods of high solar activity and therefore pose a lower overall risk. Permitting a satellite to use a smaller drag device over 25 years, which will average about two solar cycles, means it will incur about three times the risk compared with a larger device selectively operated near solar max (including the time taken waiting for solar max). As a result, the authors recommended that drag augmentation devices be sized and timed to complete their deorbit function only during solar max in order to further reduce the risk of creating new debris.

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99 Responses to Earth’s orbital debris – it’s a drag

  1. Mike Bromley the Canucklehead in Switzerland says:

    Global warming to the rescue. /sarc

  2. DaveF says:

    Maybe we could turn all this junk into a ring, like Saturn’s. Then we’d look like a real grown-up planet…. ;-)

  3. Leo says:

    Perhaps we should consider increasing the size of the orbit debris cloud in order to augment the global dimming/cooling effect of India’s and China’s economic and industrial expansion.

  4. Bloke down the pub says:

    As a result, the authors recommended that drag augmentation devices be sized and timed to complete their deorbit function only during solar max in order to further reduce the risk of creating new debris.

    So if we go into a Maunder type minimum, it’s back to the drawing board.

  5. steveta_uk says:

    What about all the super-secret satelite killing lasers that the military have secretly been putting into orbit since the 1980′s? Can’t they be used to vaporise the garbage?

  6. Doug Proctor says:

    Any one have the natural rate of debris de-orbiting is, i.e. delta debris orbit vs time? Like climate change, if we do nothing, will it/when will this problem solve itself? A lot must be in low orbits subject to atmospheric drag.

  7. Rhoda Klapp says:

    There’s more drag at solar max? More air up there? A taller atmosphere affecting pressure gradients down here and lapse rates? Higher surface temps therefrom? Well, well.

  8. I’m not really grasping the thrust (pun?) of this article. I do note, however, that the graphic is somewhat misleading as I estimate the size of each dot to be in the neighborhood of 200 miles in diameter.

    REPLY: that’s dealt with in the caption, maybe you missed it – Anthony

  9. Luther Wu says:

    Space Junkers… science fiction, first- reality, later.

  10. Martin A says:

    How big/fast would an incoming object (asteroid, comet etc) colliding with the Earth have to be to result in significant debris from the collision staying in orbit around the earth?

  11. RHS says:

    “Q” says – Why not just change the gravitational constant of the universe?

  12. Bill Parsons says:

    There’s no doubt a fleet of aerospace engineers looking at how to protect their valuable assets in space. Hypervelocity impact studies have been conducted on various materials, including carbon fiber reinforced plastics and Kevlar to face vital satellite parts. Some entrepreneur should launch several satellites with inflatable cfrp / Kevlar padding (like umpire’s chest protectors), each with small self-propulsion system. Like a big Kevlar catcher’s mitt, these could be coordinated to intercept debris objects in orbit, perhaps even utilizing impacts to re-align in new orbits, then negotiate its own decay path into the ocean. The Kevlar catcher’s mitt.

  13. Bill Parsons says:

    Is it baseball season yet?

  14. Ray says:

    Maybe the EPA could take care of that?

  15. Doug Huffman says:

    Are the units of collision cross-section Barns, as subatomic absorbtion cross-sections are, equal to 10^-24 cm^2 as I recall? Two related units are the outhouse (1 μb, or 10^−34 m^2) and the shed (10^−24 b (1 yb), or 10^−52 m^2)

  16. Owen in GA says:

    Until it becomes economically viable for someone to go collect the garbage, we will have to keep monitoring it and avoiding it on the space flights we do take.

    steveta_uk: zapping something with a laser would likely just add lots of small particles to dodge. I don’t think that would work even if the lasers were out there. Of course you probably just forgot your /sarc tag and I am taking you seriously for nothing.

    I always thought the responsible thing to do with upper stages (below the payload) was to have small deorbiting rockets on them as part of the design. Then it is just the explosive bolt pieces we have to worry about, and those can be designed so the heads are retained on the part when they blow.

  17. Jean Meeus says:

    Rhoda Klapp asked : “There’s more drag at solar max? ”
    Yes indeed, and that was discovered soon after the launch of the first artificial satellites. Higher solar activity results in higher air density, but only above about 200 kilometers.

  18. GlynnMhor says:

    Bloke suggests: “So if we go into a Maunder type minimum, it’s back to the drawing board.”

    We seem already to be in a Grand Solar Minimum that promises to be at least the equivalent of the Dalton one of the 19th century.

    It’s not a good sign for trying to clear debris from low orbits. Something else is almost certainly going to be needed.

  19. Chris4692 says:

    Simple is best. A small rocket or thruster attached to the satellite, fired at the end of it’s useful life would quickly remove it from orbit. Though that isn’t sexy enough for mention in the article the chart presented seems to indicate “Immediate and controlled propulsive deorbit” as having the least hazard. The thruster wouldn’t even necessarily have to slow it down or be immediate, just make its orbit more elliptical for more frequent contact with the atmosphere.

  20. squid2112 says:

    Why not just use photon torpedo’s and laser blasters?

  21. kent Blaker says:

    To get anything into space costs a lot of money.The should be looking at this junk as an asset, not a liability. Harvest it, don’t burn it up by de-orbiting it. Collect it for future use.

  22. nonegatives says:

    Where is Quark when we need him?

  23. Chris4692 says:
    March 26, 2013 at 9:19 am
    Simple is best. A small rocket or thruster attached to the satellite, fired at the end of it’s useful life would quickly remove it from orbit
    It is not quite that simple. It is difficult to control the point of impact. You don’t want the satellite to impact in a city or just anywhere.

  24. Kaboom says:

    30 years from now we’ll be able to deploy semi-autonomous, mass produced little robotic devices that will grab a piece of debris and decelerate it properly to burn up in the atmosphere.

  25. Nice to see an article from AIAA which I was a member from when i worked in the field back in the Apollo era. My being a member and my work back then is why this mathematician and computer scientist is still interested in climate science today.

  26. Bill Parsons says:

    Usually we don’t watch movies mid-week, but I saw the movie “October Sky” last night. Homer Hickam later wrote his own biography, “Rocket Boys”, about his experience growing up in Coalwood, Virginia, and sudden interest in rockets after watching Sputnik, the first man-made satellite, crossing overhead one night.

    http://en.wikipedia.org/wiki/Homer_Hickam

    Sputnik was launched in 1957, and came down three months later, in January, 1958. We’ve come a long way to create the cluttered mess pictured above.

  27. D.J. Hawkins says:

    nonegatives says:
    March 26, 2013 at 9:32 am
    Where is Quark when we need him?

    I’m not sure what use a Ferengi would be in this case. “Q” on the other hand could be a solution. Or not. He might just as likely turn all the debris into neutronium as clean it up.

  28. Matt says:

    Hire the Dyson corp to build a giant device to sweep up the debris and land it.

  29. _Jim says:

    Owen in GA says March 26, 2013 at 8:48 am

    I always thought the responsible thing to do with upper stages (below the payload) was to have small deorbiting rockets on them as part of the design. …

    A not-so-insignificant amount of that debris is owed to ‘packages’ that exploded late in the procedure of getting them into their planned orbit, as in the 3rd or last stage simply blew up. Nothing left but an expanding, orbiting “debris” field after an event like that …

    .

  30. Gary D. says:

    @ Jean Meeus
    How does higher solar activity increase air density above 200 kilometers?

  31. >the graphic is somewhat misleading
    “REPLY: that’s dealt with in the caption, maybe you missed it – Anthony”

    Yes, I did miss it although my comment was directed at the originator of the graphic who I know can be misleading. That’s the part you missed because you can’t read my mind.

  32. vukcevic says:

    Lot of precious metals in the debris: copper, gold, platinum, etc ….
    Larry Page with Eric Schmidt of Google, and “Avatar” director James Cameron could find more profitable hoovering this space junk than their odd enterprise to chase and mine asteroids.

  33. Jeff says:

    Doug Huffman says:
    March 26, 2013 at 8:46 am
    Are the units of collision cross-section Barns, as subatomic absorbtion cross-sections are, equal to 10^-24 cm^2 as I recall? Two related units are the outhouse (1 μb, or 10^−34 m^2) and the shed (10^−24 b (1 yb), or 10^−52 m^2)

    ….

    And of course there are the units most interesting for weather folks….the milli-barn
    (sorry…)

  34. oldfossil says:

    Leif Svalgaard says:
    March 26, 2013 at 9:38 am

    Chris4692 says:
    March 26, 2013 at 9:19 am
    Simple is best. A small rocket or thruster attached to the satellite, fired at the end of it’s useful life would quickly remove it from orbit
    It is not quite that simple. It is difficult to control the point of impact. You don’t want the satellite to impact in a city or just anywhere.

    Yes, Leif, but how large would a satellite have to be to impact the ground? The Chelyabinsk meteroid had an estimated mass of 11 metric tons with a solid quartz structure that resisted burnup. The Columbia shuttle had a mass on re-entry of about 100 tons and even massive parts like the engines didn’t reach the ground intact.

  35. DBO says:

    Years ago, I did work on effects of nuclear explosions in space. One of the major effects was something called “atmospheric heave” whereby the energy deposited in the upper atmosphere would cause a column of atmosphere to be lofted to extreme heights increasing the density at altitudes up to several hundreds of Km by orders of magnitude in an area several hundred km in diameter beneath the burst.
    So, several 1 Mt bursts at say 200 Km above the equator would do the trick for equatorial orbits.
    Perhaps a better way: The HARP facility is used to mimic effects of high atmos nuke bursts and aurora phenomena by depositing rf energy in the atmosphere. Could ti be used to locally heat the atmosphere to cause atmospheric heave to accomplish de-orbiting at any orbital inclination?

  36. Use massive nuclear explosions in high orbit to sweep all the junk into piles for more manageable deorbiting. And don’t tell me it isn’t practical or physically possible or it will damage all our satellites because I really really really want giant explosions in space.

  37. DBO says:

    Alternatively, one could use a sub-orbital rcoket to inject a cloud of something like Tungsten Fluoride gas also in an “almost full orbit” to cause de-orbit of very small objects. Small objects have high ratio of surface area to mass so are easier de-orbited this way.

    My favorite scheme is to use lunar dust. We electrically charge lunar dust and use This dust would be fired toward earth using electrostatic fields where it would do the same thing as a dense atmosphere, momentum exchange and help de-orbit stuff. Some of the dust would enter the atmosphere (fantastic light show) and rest would exit the earth-moon system due to its velocity.

  38. Crashex says:

    “Homer Hickam later wrote his own biography, “Rocket Boys”, about his experience growing up in Coalwood, Virginia,…”

    That should be WEST VIRGINIA. (Let’s not start a fight.)

  39. _Jim says:

    DBO says March 26, 2013 at 11:09 am

    My favorite scheme is to use lunar dust. We electrically charge lunar dust and use This dust would be fired toward earth using electrostatic fields where it would do the same thing as a dense atmosphere, momentum exchange and help de-orbit stuff. …

    Including de-orbiting useful satellites still in service?

    Marvellous, dahling, just marvellous …

    .

  40. Leo Morgan says:

    I’d love to know the figures they used. It’s not that I doubt the figures; I just don’t know them, and it’s interesting stuff. There are many thousands of sattelites there, but there are also many millions of cubic miles of empty space.
    Aren’t they pretty near stationary with respect to each other? Because they’d be in different orbits if they weren’t? Presumably I’m wrong, but I’d like to know why I am.
    Each kilo in Low Earth Orbit cost 10 to 11 thousand dollars to get it there. All that lovely mass in orbit and we can’t find a way to use it?

  41. nonegatives says:

    D.J. Hawkins says:
    March 26, 2013 at 9:59 am

    nonegatives says:
    March 26, 2013 at 9:32 am
    Where is Quark when we need him?

    I’m not sure what use a Ferengi would be in this case. “Q” on the other hand could be a solution. Or not. He might just as likely turn all the debris into neutronium as clean it up.

    Sorry, should have been more specific! Quark from 1978 – United Galaxy Sanitation Patrol
    http://en.wikipedia.org/wiki/Quark_%28TV_series%29

  42. _Jim says:

    DBO says March 26, 2013 at 11:00 am

    So, several 1 Mt bursts at say 200 Km above the equator would do the trick for equatorial orbits.
    Perhaps a better way: The HARP facility is used to mimic effects of high atmos nuke bursts and aurora phenomena by depositing rf energy in the atmosphere. Could ti be used to locally heat the atmosphere to cause atmospheric heave to accomplish de-orbiting at any orbital inclination?

    The (ahem) H. A. A. R. P. facility steerable ‘planar’ (RF active elements/individual antennas situated in 12 rows x 15 columns exist on a ‘plane’ or flat area) array has limited ability to phase-steer it’s beam, making this impractical exc. for the range it is capable of ‘seeing’ (being steered) overhead (IOW, it is not effective from horizon to horizon) from its location at about 62.4 degrees North latitude.

    .

  43. john robertson says:

    Seems an awful waste not to find a space utilization for the debris.
    We spent a lot of energy to get it up the gravity well, a tar baby type collector might be more practical than directing these treasures back into the atmosphere.
    What about remote control vehicles to clump the pieces at specific orbits?
    An extension of the drone technology seems possible.
    Military training op?
    Or new life for the space station?

  44. Greg says:

    ” Permitting a satellite to use a smaller drag device over 25 years, which will average about two solar cycles, means it will incur about three times the risk compared with a larger device selectively operated near solar max (including the time taken waiting for solar max).”

    The wait for the next solar “max” worthy of the name maybe rather longer than expected by the author. ;)

  45. lsvalgaard says:

    oldfossil says:
    March 26, 2013 at 10:58 am
    The Chelyabinsk meteroid had an estimated mass of 11 metric tons with a solid quartz structure that resisted burnup.
    More like 10,000 tons.

    The Columbia shuttle had a mass on re-entry of about 100 tons and even massive parts like the engines didn’t reach the ground intact.
    ‘Intact” do you men in working order? :-)
    http://en.wikipedia.org/wiki/Space_Shuttle_Columbia_disaster :
    “More than 2,000 debris fields were found in sparsely populated areas from Nacogdoches in East Texas, where a large amount of debris fell, to western Louisiana and the southwestern counties of Arkansas. Along with pieces of the shuttle and bits of equipment, searchers also found human body parts, including arms, feet, a torso, and a heart.[25]
    In the months after the disaster, the largest-ever organized ground search took place.[26] NASA issued warnings to the public that any debris could contain hazardous chemicals, that it should be left untouched, its location reported to local emergency services or government authorities, and that anyone in unauthorized possession of debris would be prosecuted. “

  46. oldfossil says:

    John Robertson, re tar babies. How about a really big sheet of aerogel?

  47. RHS says:

    I’m against massive nuclear explosions in the atmosphere, the resulting EMP would cause significantly more damage here on the surface than it would clean up in space.

  48. Bloke down the pub says:

    john robertson says:
    March 26, 2013 at 11:37 am
    ~~~~~~~~~~~~
    If we ever get to the stage where we can build a space elevator, it will require a counter-balance in geo-stationary orbit. Then it will be useful to have all that stuff up there already.

  49. Mac the Knife says:

    Bloke down the pub says:
    March 26, 2013 at 12:07 pm
    If we ever get to the stage where we can build a space elevator, it will require a counter-balance in geo-stationary orbit. Then it will be useful to have all that stuff up there already.

    Bloke,
    That is a valid insight. The cost to launch all of that now obsolescent hardware probably averaged $10,000/lb delivered to orbit or more (that’s an amount used as a rough rule of thumb for many launch systems in the 1980 – 2000 time frame). We have a sizable investment in orbital mass already. Why repeat it at needless cost…..
    MtK

  50. DesertYote says:

    steveta_uk says:
    March 26, 2013 at 7:43 am

    What about all the super-secret satelite killing lasers that the military have secretly been putting into orbit since the 1980′s? Can’t they be used to vaporise the garbage?
    ###

    Ok, I’ll bite. Won’t work. At best just make a bunch of smaller junk. Spaced based laser systems also have the nasty habit of deorbiting every time they are fired. The shiny metal surfaces of much space junk also tends to just reflect more energy the absorbed. The energy that is absorbed goes into vaporizing small amounts of material that push the target into new orbits.

  51. DesertYote says:

    nonegatives says:
    March 26, 2013 at 11:33 am

    D.J. Hawkins says:
    March 26, 2013 at 9:59 am

    nonegatives says:
    March 26, 2013 at 9:32 am
    Where is Quark when we need him?

    I’m not sure what use a Ferengi would be in this case. “Q” on the other hand could be a solution. Or not. He might just as likely turn all the debris into neutronium as clean it up.

    Sorry, should have been more specific! Quark from 1978 – United Galaxy Sanitation Patrol
    http://en.wikipedia.org/wiki/Quark_%28TV_series%29
    ###

    The other Quark, would contract out the work AND still make a handsome profit.

  52. Mike Rossander says:

    Lee Morgan at 11:26 asks “Aren’t they pretty near stationary with respect to each other? Because they’d be in different orbits if they weren’t?”

    I think the question assumes that every piece of the debris is in a stable, long-term, circular and equatorial orbit. When you violate any of those assumptions, it is possible for two pieces of debris to be in their own orbits and yet for the orbits to cross.

    The most significant failure in the assumption is that the orbits are all equatorial. That’s generally true for the geostationary satellites (and true to a lesser extent for the debris created by them) but it is untrue for the vast majority satellites which follow a circumpolar orbit. Circumpolar is what allows one satellite to map the entire globe as it rotates beneath it. Circumpolar necessarily means that those orbits are crossing at or near the poles. (Sinusoidal orbits will also cross but at different points.)

    The second most significant failure is the assumption that the orbits are circular. The original satellites were (probably) put into a circular orbit but whatever accident turned them into debris probably also perturbed the orbit into an elliptical. It will be moving in and out relative to earth, gaining and losing speed as it does so and crossing the circular orbits (and other elliptical orbits) along the way.

    The result is that, no, you can not assume the debris is stationary with respect to each other. They are quite dynamic. The only thing preventing them all from smashing into each other today is the vastness of space. Well, that and the fact that in a vacumn, a near miss is still a complete miss. It doesn’t matter whether you missed by a quarter inch or a dozen miles – there is no atmosphere to transfer any effect of a “near miss”.

  53. StanleySteamer says:

    In 2000, working as a Boeing engineer, I proposed the Boeing develop a company called Space Scavengers which would focus on several issues related to space junk. I have some experience with this topic as I spent one summer in the early 1970′s as an Orbital Analyst at NORAD (Air Force Academy third lieutanant program) where I performed orbital decays of space junk. A summary of my plan was to establish several initiatives concerning this problem. First, was the development of two small vehicles at the ISS named “Rover” and “Dolphin” . Rover’s mission would be to retrieve any object that broke free from the ISS. Dolphin’s mission would be to retrieve any astronaut who broke free from the ISS. Second, we need a space based interceptor based at the ISS that has the capability to seek out and destroy any junk that exists in the ISS’s orbital plane. Third, we need to investigate, as the technology matures, small, robotic,satellites that could “piggy-back” on another launch and then be deployed to retrieve high value space junk. These robots could use advanced propulsion systems and technologies to retrieve objects from as far away as geo-synchronous orbit. They could operate independently or as a unit to change the orbit of any satellite using solar sails/balloons/inflatible head shields/etc.. Finally, I proposed that we could eventually move into the rescue and repair business perhaps by locating a facility near the ISS. This proposal was quickly shot down by Boeing Space and Defense as an unworkable idea. I still have that proposal and it was interesting to dust it off and see that the problem hasn’t gone away.

  54. RHS says:

    The geostationary orbit is roughly 35,786 kilometres (22,236 mi) above the Earth. Satellites such as communications and weather satellites typically are in this orbit. Where a helio/Sun-synchronous orbit is 600 – 800 km above the earth. These make an orbit every 85 – 120 minutes. I believe these are the ones with the biggest risk from space debris as there is less “space” in the orbit.

  55. RHS says:

    To give an idea of how fast everything flies around in orbit, several years ago one of the Space Shuttles cracked a windshield while in orbit. The glass was at least two inches thick and was considered bullet resistant. Any idea’s what cracked it? A tiny piece of paint…

  56. A.D. Everard says:

    Leave it be. Earth looks after itself and the junk will be cleared out of orbit quite naturally. If we lose some satellites along the way, so be it. If we stop wasting quarter of a $million on every windmill, we’ll have enough to replace the satellites – no worries. :)

  57. MarkW says:

    Leif Svalgaard says:
    March 26, 2013 at 9:38 am

    Very few satellites have enough mass to make it through the atmosphere. Even then the few parts that do will be small enough to have pretty low terminal velocities.

  58. MarkW says:

    _Jim says:
    March 26, 2013 at 11:23 am
    Including de-orbiting useful satellites still in service?
    —-
    Intact satellites would have a much higher mass to surface area ratio and wouldn’t be as strongly affected.

  59. MarkW says:

    DesertYote says:
    March 26, 2013 at 12:43 pm

    Ok, I’ll bite. Won’t work. At best just make a bunch of smaller junk. Spaced based laser systems also have the nasty habit of deorbiting every time they are fired. The shiny metal surfaces of much space junk also tends to just reflect more energy the absorbed. The energy that is absorbed goes into vaporizing small amounts of material that push the target into new orbits.

    What about a lower powered laser fired in such a way that the debris is slowed down?

  60. Bryan A says:

    @ Gary D.
    March 26, 2013 at 10:36 am
    @ Jean Meeus
    How does higher solar activity increase air density above 200 kilometers?
    As altitude increases, the atmosphere becomes thinner and drag lessens. The atmosphere is a gas and as it is cooled, it will contract slightly becoming thinner at a lower altitude. As it warms it Puffs up and becomes thicker at higher altitudes. As the Sun progresses to Solar Max it brings more energy to the atmosphere causing it to warm up and Expand outward (Puff up) to a cerrtain degree. This heat expansion causes increased drag at higher altitudes.

  61. Walter Royal says:

    I would favor building an orbital factory/processing center in geosynchronous orbit or at one of the Libration/Lagrange points and send drones with a basket or scoop up front through the debris fields in large elliptical orbits so they pass into and then out of the fields on the outside and after several passes they have a full payload and then return to the processing facility. This would have many benefits besides cleaning up the junk. It would facilitate the colonization of the libration points and get humans into space in significant numbers, boost the economy just like the original space race did, and provide the needed stepping stone to Mars, Io, and Ganymede etc.

  62. Dodgy Geezer says:

    Does anyone know what happens to a cloud of gas if you launch it from an orbiting craft?

    If such a cloud could be introduced into a high orbital plane (ideally traveling in the opposite direction to the debris) it might be a simple retarder/deorbiter…?

  63. MyTheory says:

    DesertYote says:
    March 26, 2013 at 12:43 pm

    steveta_uk says:
    March 26, 2013 at 7:43 am

    What about all the super-secret satelite killing lasers that the military have secretly been putting into orbit since the 1980′s? Can’t they be used to vaporise the garbage?

    Ok, I’ll bite. Won’t work. At best just make a bunch of smaller junk. Spaced based laser systems also have the nasty habit of deorbiting every time they are fired. The shiny metal surfaces of much space junk also tends to just reflect more energy the absorbed. The energy that is absorbed goes into vaporizing small amounts of material that push the target into new orbits.

    I think that classified military programs are usually 20-30 years ahead of what the public sees. For instance note the 747 that flew around with the impractical gas laser cannon for public demo, then suddenly the Navy is fielding ship based solid state high energy laser systems for missile knock down. That would make a fairly good case for a classified orbital laser system. Now such a system could just pull ahead of the debris and use the high energy lasers to de-orbit it through material out gassing of lower melting point material and some slowdown from laser reflection. However the military would (perhaps) have to admit to such systems.
    My best conspiracy theory is that the military has very advanced flight propulsion systems under wraps (perhaps akin to those pesky UFO’s), but they will never go for public use because they don’t want “our enemies” (everyone but us) to have them. Now if some one like China were to quietly develop such systems commercially and then quickly put them in operation, they could pretty much own everyone.

  64. Eric Worrall says:

    All that useful material, in almost stable orbits, some of it in almost useful orbits – who the hell wants to de-orbit it? Surely better to attach say nanoscale robotic solar sails, launched from a HARP style ballistic launcher, guide the material to somewhere useful where it could be used for construction.

    http://en.wikipedia.org/wiki/Project_HARP

    At around $4000+ / kg launch costs, even small scraps are potentially useful, if a way can be found to guide them to where they are needed.

  65. RHS says: March 26, 2013 at 8:35 am
    “Q” says – Why not just change the gravitational constant of the universe?

    No, that would adversely affect climate models.

    Chris4692 says: March 26, 2013 at 9:19 am
    … The thruster wouldn’t even necessarily have to slow it down or be immediate, just make its orbit more elliptical for more frequent contact with the atmosphere.

    It would have to slow the satellite for the ellipse to dip to lower, denser altitudes.

    Mac the Knife says: March 26, 2013 at 12:32 pm
    … The cost to launch all of that now obsolescent hardware probably averaged $10,000/lb delivered to orbit or more …

    Once the velocity of money picks up, inflation from all this insane deficit spending will be upon us and $10,000/lb will be the price of steak.

    StanleySteamer says: March 26, 2013 at 1:40 pm
    … I have some experience with this topic as I spent one summer in the early 1970′s as an Orbital Analyst at NORAD (Air Force Academy third lieutanant program) where I performed orbital decays of space junk.

    Third Looie in a cave in the Zoo’s back yard? You must have p.o.’d somebody. I was back seat in F4′s in sunny Tucson. ;-)

    Matt says: March 26, 2013 at 10:19 am
    Hire the Dyson corp to build a giant device to sweep up the debris and land it.

    Or the Tyrell Corp.

    I do like the idea of a Kevlar catcher’s mitt. We’ll need it to protect the space elevator, which will be getting full velocity impacts from anything that hits it.

  66. lsvalgaard says:

    MarkW says:
    March 26, 2013 at 2:01 pm
    Very few satellites have enough mass to make it through the atmosphere. Even then the few parts that do will be small enough to have pretty low terminal velocities.
    http://www.edn.com/electronics-blogs/edn-moments/4405598/Satellite-scatters-radioactive-debris-over-Canada–January-24–1978

  67. _Jim says:

    MarkW says March 26, 2013 at 2:06 pm

    Intact satellites would have a much higher mass to surface area ratio and wouldn’t be as strongly affected.

    then continuing -

    DBO says March 26, 2013 at 11:09 am

    This dust would be fired toward earth using electrostatic fields …

    OH LOVELY; the charged dust is going to stick uniformly all over the satellite’s surface (including the solar panels) like flies on dog do-do, white-on-rice, IRS/tax collectors-on-taxpayers!

    .

  68. _Jim says:

    RHS says March 26, 2013 at 1:51 pm

    The geostationary orbit is roughly 35,786 kilometres (22,236 mi) above the Earth. Satellites such as communications and weather satellites

    But this does not include a very useful and not so obscure set of sats such as:

    GPS, Glonass or Galileo nav sats,
    Iridium and Globalstar comm sats,
    polar orbiting wx sats,
    satellite broadcasters e.g. XM,
    HAM (amateur) sats,
    and the Orbcomm small data-packet comm sat constellation …

    right off the top of my head …

    .

  69. Matthew W says:

    OMG!!!!!
    We’ve screwed up the planet and now space !!!
    It is worse than we thought.

    It is a serious problem though.

  70. K says:

    Powered or controlled de-orbiting involves legal liability under the laws of space treaty. If left uncontrolled, the launching country has a lower liability. Have the proponents of these concepts considered the laws involved?

  71. usurbrain says:

    Has any correlation been made between the number of satellites and global warming?

  72. LarryD says:

    Re: atmospheric “puffing”
    We saw this back during the solar minimum, when the troposphere contracted. While the total solar output doesn’t change much, the amount in the ultraviolet region dropped significantly, that might be the driver.

  73. 1phobosgrunt says:

    lsvalgaard says:
    March 26, 2013 at 4:12 pm
    MarkW says:
    March 26, 2013 at 2:01 pm
    Very few satellites have enough mass to make it through the atmosphere. Even then the few parts that do will be small enough to have pretty low terminal velocities.
    http://www.edn.com/electronics-blogs/edn-moments/4405598/Satellite-scatters-radioactive-debris-over-Canada–January-24–1978

    We can hope for more of them to fall into the ocean?

    Russia’s Failed Mars Probe Crashes Into Pacific
    By ANDREW E. KRAMER
    Published: January 15, 2012
    . A Russian scientific probe that was meant to visit a Martian moon but never made it out of Earth orbit crashed into the Pacific Ocean about 700 miles west of Chile on Sunday, a Russian military spokesman said.
    The Phobos-Grunt spacecraft had been circling Earth since shortly after its launching on Nov. 9, losing a few miles of altitude each day until it fell into the atmosphere. The 13-ton ship was one of the heaviest manmade objects yet to make an uncontrolled plunge back to Earth, though most of its weight was fuel and probably burned up during re-entry.

    ..As Phobos-Grunt broke up and burned on re-entry, the Russian space agency said, as many as about two dozen pieces might have reached the surface, weighing a total of about 400 pounds. …
    http://www.nytimes.com/2012/01/16/science/space/russias-phobos-grunt-mars-probe-crashes-into-pacific.html?_r=0

  74. Larry Ledwick (hotrod) says:

    One of the big problems is how do you intercept something that is so small and moving so fast that it is almost impossible to track with a reasonable sized on orbit sensor. If you can do that, there is at least one class of material that could be de-orbited without any additional generation of debris. Any magnetic or para-magnetic material could be slowed down by passing it through a strong magnetic field on closest approach to the capture device.

    For example a large tubular device about the size of a shuttle fuel tank with strong electro magnets positioned so the debris item passed down the axis of the device, on the inbound side of its elliptical orbit toward perigee. A piece of aluminum for example would be strongly slowed as it passed through the magnetic field inside the device. Iron would have to have the magnetic field activated only after the debris object is near the center of the device so it only would see deceleration as it moved out of the capture device.

    The bad news is this is probably not logistically or financially possible but in theory would work.

    A similar approach for a “catchers mitt could be devised for non-magnetic or non-para-magnetic materials like paint chips or plastic. It would have to be a deep cylinder perhaps tapering with multiple thin membranes across the tube with a dead end able to survive final impact. In effect you would be have a very deep whipple shield contained inside an open ended “trash” can. Sort of a roach motel for orbital debris, it checks in but does not get back out. Each successive membrane impact would deplete energy and break up the object into small enough pieces it can be contained inside the can. To prevent the generated debris from exiting the can, you would have two methods at work. First the debris would have to find its way back out through all the membranes by passing through one of the holes generated by previous impacts. This would be geometrically difficult, odds of a bit of generated debris being on the right flight path to pass back out one of these small openings would be very small. The other would be inertial capture, by having the “trash can” accelerate briefly shortly after the impact so that the debris “falls” to the bottom of the can, and becomes more stuff that a newly arriving piece of space junk could impact to shed velocity.

    Again possible for certain objects of high concern, but probably too expensive to be economically affordable, and the logistics overhead of managing even a single capture would involve a lot of people and data processing capability.

    No easy fix on this one but it could be done with enough will and investment of time and resources.

    Larry

  75. Dan in California says:

    Leo Morgan says: March 26, 2013 at 11:26 am
    I’d love to know the figures they used. It’s not that I doubt the figures; I just don’t know them, and it’s interesting stuff. There are many thousands of sattelites there, but there are also many millions of cubic miles of empty space.
    Aren’t they pretty near stationary with respect to each other?
    ————————————————————–
    As an example, assume you are on the ISS at 400 km altitude and you release a satellite with no relative velocity. Six months later that sub satellite will be in an orbit far different from ISS. Because the ballistic coefficients are different, atmospheric drag will have moved the two objects into different orbital planes and slightly different altitudes. I worked on the now-cancelled Orbital Maneuvering Vehicle (OMV) which was supposed to release and fetch just such satellites. We learned that after a few months, no reasonable space “tug” could go get the released satellite. If the orbits intersected then, the relative velocity would be several hundred meters/sec, quite enough to destroy both vehicles.

    As for the atmospheric drag question, ISS needs reboost multiple times per year, and this is done with the docked Soyuz or Progress tankers. Skylab was supposed to be rescued (reboosted) by using the new Space Shuttle, but Solar Max raised the atmosphere which increased drag more than assumed. That plus delays in the Shuttle program combined to lose that big space station.

  76. JohnB says:

    I’d go with the factory idea. We spent a fortune getting the stuff up there and letting it go to waste is silly. It is so much cheaper to change orbits than to get the new stuff up there.

    There was a book years ago where this was the central characters main job, going out and getting the old boosters and satellites to be melted down and reworked to extend the station. Damned if I can remember the name but the craft used was nothing more than motors, fuel, a computer to work out and control the burns and a seat for the pilot.

    It’s also worth while to remember that those sats which failed early in their lives probably still have full fuel tanks for their thrusters. Might it be possible to use the fuel from dead sats to refuel some of the good ones and extend their lives?

    Such a facility would be expensive, but launches are worth over $200 billion per year now. Note that the same craft used to recover junk could rescue a sat that failed separate from the booster and place it in the correct orbit. Paying the station to do that would be far cheaper than paying for a new sat and launch. So the station gets the recovery fee and a nice new booster for fresh materials as well.

  77. Bill Woods says:

    Bill Parsons says: ‘Usually we don’t watch movies mid-week, but I saw the movie “October Sky” last night. Homer Hickam later wrote his own biography, “Rocket Boys”, …’

    Other way around — the movie was based on Hickam’s book.

  78. jon shively says:

    I spent several years working on a project for the Department of Defense on the implications of space debris for satellite life in low earth orbit, (100 miles). Since the days of Sputnik we and others have added steadily to the flux of debris traveling around the earth at hypervelocities, 10 to 20 km/sec. The debris is not aligned indirection and can be in counter directions. The picture is very misleading because the velocity distribution of particles is varies with latitude and longitude and the spacing is very sparse. Large particles are being tracked and monitored. Several times the space station was moved slightly to avoid a collision with space junk.
    I doubt that anyone would able to come up with an inexpensive way to capture or de-orbit the very small pieces of junk. The LDEF satellite which spent several years in orbit before it was rescued by the space shuttle has impacts on numerous surfaces from small particles of debris but none were catastrophic. Probably space junk is not a major problem facing the space program when one considers that the size of the NASA budget continues to shrink. Since the likelihood of a major collision with a satellite is low, when it happens it might be cheaper to replace the satellite than to launch a vehicle to collect space junk.

  79. Bill Woods says:

    steveta_uk says: “What about all the super-secret satelite killing lasers that the military have secretly been putting into orbit since the 1980′s? Can’t they be used to vaporise the garbage?”

    DesertYote says: “… The energy that is absorbed goes into vaporizing small amounts of material that push the target into new orbits.”

    That’s the intended result of the laser. Zapping an approaching bit of debris with a ground-based laser vaporizes a layer of the target which, per Newton’s 3rd, gives it a slight de-orbiting burn.
    http://en.wikipedia.org/wiki/Laser_broom

  80. DesertYote says:

    MarkW says:
    March 26, 2013 at 2:10 pm

    DesertYote says:
    March 26, 2013 at 12:43 pm

    Ok, I’ll bite. Won’t work. At best just make a bunch of smaller junk. Spaced based laser systems also have the nasty habit of deorbiting every time they are fired. The shiny metal surfaces of much space junk also tends to just reflect more energy the absorbed. The energy that is absorbed goes into vaporizing small amounts of material that push the target into new orbits.

    What about a lower powered laser fired in such a way that the debris is slowed down?
    ###

    The laser wielding killer satellite would still have to deal with its change of momentum caused by changing the momentum of the target, but this is getting closer to a workable system. Also note that the killer would be pushed into a higher orbit and the target into a lower, so the target would be over taking the killer at some point ( change is perpendicular to the axis of force, vector multiplication and all that).

  81. tobias says:

    Kirk to Scottie,
    “Don’t beam me up Scottie”

  82. Bart says:

    US Government mitigation standard practices call for maneuvering to limit orbital lifetime to 25 years after the end of the mission when possible. NASA has been requiring this for its maneuverable satellites below an altitude of 2000 km since 2007. GEO birds must be shifted to a graveyard orbit at end of life. 

    An impact risk assessment for any components which might survive reentry is required as part of the design process. That risk has to be tiny, in accordance with established criteria.

    The problem is, what do you do about all the debris which is already up there? And, how do we deal with the potential of a cascade effect, in which one collision creates a much broader cross section for impact, leading to additional impacts, and so on, and so on…

  83. Konrad says:

    Many years ago it was proposed to destroy icebergs in shipping lanes by spreading carbon black on their sunlit surfaces to melt them.
    http://www.navcen.uscg.gov/?pageName=photoGallery&photoGalleryId=4
    This proved ineffective as the icebergs tended to roll as they melted and their balance changed.

    However a similar idea was later floated for the deflection of incoming comets. In this small rockets fly to the comet and detonate ahead of the comet and spread carbon black over its surface. Heliostat arrays in earth orbit then focus intermittently on the comet and use the boil off of ice as propellant to deflect the main mass of the comet. However it was later found that most comets already have a dark surface.

    It may be possible to reuse some of these ideas to de-orbit space debris. An orbital heliostat mirror array has far more potential power than any laser currently available. Most high powered missile destroying lasers are gas lasers that require consumables. A heliostat mirror array is powered by the sun.

    A better use of available consumables payload would be dark ice balls. Rather than firing the mirror array at the debris directly (which would likely cause secondary fragmentation), it could be focused just ahead of the debris along its orbit. Ice balls of frozen water and black dye could then be fired into the focus. The resulting steam explosion would alter the velocity of the approaching debris. These steam explosions could be used multiple times on larger elements and altering focus and detonation points could allow trajectory adjustment of the debris. Aiming the mirror array and ice balls would not require the precision or sophistication of rockets that intercept and attach. Any un-vaporised ice balls and fragments would soon vaporise in sunlight due to their black dye without adding to materials in orbit. Such as system could be used against a wide range of targets.

    The removal of the smallest particles may have to wait for the increased drag of an atmosphere expanded to near pre 2000 levels which should occur again some time after 2035. Sorry Leif ;)

  84. Chris4692 says:

    Leif Svalgaard says:
    March 26, 2013 at 9:38 am

    Chris4692 says:
    March 26, 2013 at 9:19 am
    Simple is best. A small rocket or thruster attached to the satellite, fired at the end of it’s useful life would quickly remove it from orbit
    It is not quite that simple. It is difficult to control the point of impact. You don’t want the satellite to impact in a city or just anywhere.

    If it is the case that control of the point of impact is so critical, how do the other methods, which are designed to slowly decay the orbit over many years, control the point of impact?

  85. lsvalgaard says:

    Chris4692 says:
    March 26, 2013 at 9:43 pm
    If it is the case that control of the point of impact is so critical, how do the other methods, which are designed to slowly decay the orbit over many years, control the point of impact?
    Read here about de-orbit strategy http://esamultimedia.esa.int/docs/gsp/completed/comp_i_01_N13.pdf

  86. DesertYote says:

    Bill Woods says:
    March 26, 2013 at 8:36 pm

    steveta_uk says: “What about all the super-secret satelite killing lasers that the military have secretly been putting into orbit since the 1980′s? Can’t they be used to vaporise the garbage?”

    DesertYote says: “… The energy that is absorbed goes into vaporizing small amounts of material that push the target into new orbits.”

    That’s the intended result of the laser. Zapping an approaching bit of debris with a ground-based laser vaporizes a layer of the target which, per Newton’s 3rd, gives it a slight de-orbiting burn.
    http://en.wikipedia.org/wiki/Laser_broom
    ###

    My comment was about the infeasibility of vaporizing the target. I address some points related to using lasers to deorbit the target in another comment. One difference between ground based lasers and space based, is that with ground based, the “equal but opposite” accelerates the earth, which only a climate scientist would be able to detect, while a space based would accelerate the platform … that whole conservation of momentum bit. Doesn’t matter that the momentum is being carried by photons; photons, electrons, atoms, all the same.

  87. Electromagnetic tethers are the only viable and cost effective method of deorbiting these satellites. The problem is not technical but legal. Most of the debris out there is of Russian origin and the Russians will not give permission to access their property.

  88. oldfossil says:

    lsvalgaard says:
    March 26, 2013 at 11:49 am

    oldfossil says:
    March 26, 2013 at 10:58 am
    The Chelyabinsk meteroid had an estimated mass of 11 metric tons with a solid quartz structure that resisted burnup.
    More like 10,000 tons.

    The Columbia shuttle had a mass on re-entry of about 100 tons and even massive parts like the engines didn’t reach the ground intact.
    ‘Intact” do you men in working order? :-)
    http://en.wikipedia.org/wiki/Space_Shuttle_Columbia_disaster :
    “More than 2,000 debris fields were found in sparsely populated areas from Nacogdoches in East Texas, where a large amount of debris fell, to western Louisiana and the southwestern counties of Arkansas. Along with pieces of the shuttle and bits of equipment, searchers also found human body parts, including arms, feet, a torso, and a heart.[25]
    In the months after the disaster, the largest-ever organized ground search took place.[26] NASA issued warnings to the public that any debris could contain hazardous chemicals, that it should be left untouched, its location reported to local emergency services or government authorities, and that anyone in unauthorized possession of debris would be prosecuted. “

    Leif, thanks for your reply.

    While you were at that wiki page I hope you looked at the jpg of the collected debris being reconstructed in a hangar. I saw two large objects: the axle of the front undercarriage, and some large-ish round shiny thing from the nose. They might possibly have caused substantial damage if they landed in a built-up area — wrecked a house for example.

    Thousands of meteorites fall out of the sky every day. At a terminal velocity of 200 km/h, some are large enough to kill any human they hit. I’m scratching my brains to think of the last time I heard of anyone killed or even injured by a meterorite!

  89. lsvalgaard says:

    oldfossil says:
    March 27, 2013 at 5:37 am
    I’m scratching my brains to think of the last time I heard of anyone killed or even injured by a meterorite!
    Stop scratching: Chelyabinsk
    Safe de-orbiting is a real issue that is taken seriously:
    http://esamultimedia.esa.int/docs/gsp/completed/comp_i_01_N13.pdf

  90. Bill Woods says:

    DesertYote says: “… One difference between ground based lasers and space based, is that with ground based, the “equal but opposite” accelerates the earth, which only a climate scientist would be able to detect, while a space based would accelerate the platform … that whole conservation of momentum bit. Doesn’t matter that the momentum is being carried by photons; photons, electrons, atoms, all the same.”
    The momentum of photons is pretty trivial. While it’s firing, a 1-MW laser would experience a recoil of only 3 mN, and the most it could deliver to a target is twice that. The way to really move the target is to heat its surface enough to blow off a thin layer.

  91. From the looks of it, it going to be simpler & (perhaps several orders of magnitude) cheaper to just ignore the debris & launch a new satellite when one of ‘em gets mashed.

    In the case of a[n already] massive waste of money like the ISS, we can track & de[stroy|orbit] anything that seems like it might cause specific problems there.

  92. Mac the Knife says:

    Mike McMillan says:
    March 26, 2013 at 3:46 pm
    Mac the Knife says: March 26, 2013 at 12:32 pm
    … The cost to launch all of that now obsolescent hardware probably averaged $10,000/lb delivered to orbit or more …

    Once the velocity of money picks up, inflation from all this insane deficit spending will be upon us and $10,000/lb will be the price of steak.

    Mike,
    I whole heartedly agree with you on the insanity of our huge deficits, national debt, and ‘buying’ our own Treasury issued bonds/bills/notes with unsupported, newly printed ‘money’, because the rest of the world will no longer buy all of our debt! We are ‘monetarily easing’ our way into bankruptcy, with Russia,China, and Iran cheering us on.

    However, the past investments in mass launched to orbit (roughly $10,000/lb) is a done deal. The looming inflation will increase the dollar cost of that investment, much the same way it has increased/inflated the dollar cost of gold over time.

    From a pragmatic and historic perspective, those orbiting boosters and satellites are potential gold mines on the new frontier! What we learn about the economics and practicality of mining these resources in near earth orbit will provide the lessons learned necessary to take the ‘next step’: Capturing and setting up mining and manufacturing operations on high metal fraction asteroids.
    MtK

  93. beng says:

    ***
    oldfossil says:
    March 26, 2013 at 10:58 am
    The Chelyabinsk meteroid had an estimated mass of 11 metric tons with a solid quartz structure that resisted burnup.
    ***

    It’s about speed. Meteors are far faster than orbital stuff, so burn-up of a given mass is much more likely for a meteor than a piece of spent-rocket.

  94. DesertYote says:

    Bill Woods says:
    March 27, 2013 at 10:41 am

    DesertYote says: “… One difference between ground based lasers and space based, is that with ground based, the “equal but opposite” accelerates the earth, which only a climate scientist would be able to detect, while a space based would accelerate the platform … that whole conservation of momentum bit. Doesn’t matter that the momentum is being carried by photons; photons, electrons, atoms, all the same.”
    The momentum of photons is pretty trivial. While it’s firing, a 1-MW laser would experience a recoil of only 3 mN, and the most it could deliver to a target is twice that. The way to really move the target is to heat its surface enough to blow off a thin layer.
    ####

    Sorry for taking so long to reply. I’ve been rather sick. Don’t get me wrong. I was not discounting the viability of using space based lasers to deorbit junk, as I indicated in my first comment on this subject. I was just pointing out the fact that firing a laser would change the orbit of the lasers platform. BTW, a laser used in this way would be a pulsed laser and not continuous fire which simplifies some things but makes others more complicated. Regardless, the platform would have to be very maneuverable or else it would be useless for the task. I’d love to write the targeting software.

  95. john robertson says:

    30 years ago I thought we were going somewhere with space exploration and exploitation, where we are today is a bit sad.
    Maybe the private boys will succeed, I sure hope so, as all we can do right now is cower at the bottom of this gravity well and pray the asteroids keep missing.
    Very similar to the way we cower in fear from the group psychosis of the eco-doom religions.
    Thanks WUWT, without this help I would still be afraid that the collective was nuts, rather than a loud mouthed minority.

  96. Lawrence of Suburbia says:

    There’s a trash hauling outfit in Passaic, NJ…the Marucci Brothers…that’ll do the job for a small fee. They’ll get some trucks and containers up there and take care of the problem…capish?

  97. Bill Woods says:

    Stark Dickflüssig says: “From the looks of it, it going to be simpler & (perhaps several orders of magnitude) cheaper to just ignore the debris & launch a new satellite when one of ‘em gets mashed.”
    —-
    The trouble is that collisions between debris & satellites, and debris & debris, generate *more* bits of debris. The end result could render low Earth orbit too dangerous to use.
    http://en.wikipedia.org/wiki/Kessler_syndrome

  98. NASA and MDA (current owner of the Canadarm manipulator product used on the space shuttle and international space station) have toyed with developing robotic equipment to repair satellites (in effect unmanned space devices).
    Should be usable to grab defunct satellites to get them out of orbit, but need a sizeable bag to hold them?
    Size of pieces varies of course, from whole satellites to very small pieces that still endanger active satellite – need special method for those?
    I do like the concept of keeping the mass in orbit by somehow re-using it, but that takes processing to separate materials, which takes a facility. That’s costly, even more so with quantities of humans who require life support systems.
    Owners of active satellites should be happy to pay to get rid of the debris they have to maneuver their satellites around.

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